ASTM D2525-1990(2008) Standard Practice for Sampling Wool for Moisture《测定羊毛水分的取样的标准实施规程》.pdf
《ASTM D2525-1990(2008) Standard Practice for Sampling Wool for Moisture《测定羊毛水分的取样的标准实施规程》.pdf》由会员分享,可在线阅读,更多相关《ASTM D2525-1990(2008) Standard Practice for Sampling Wool for Moisture《测定羊毛水分的取样的标准实施规程》.pdf(5页珍藏版)》请在麦多课文档分享上搜索。
1、Designation: D 2525 90 (Reapproved 2008)Standard Practice forSampling Wool for Moisture1This standard is issued under the fixed designation D 2525; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、 in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the design of a sampling plan to beused to obtain samples for the determination of the moisturecontent of grease wool, s
3、coured wool, carded wool, garnettedwool, wool top and intermediate products, and rovings.1.2 Directions are given for the designation of samplingunits, calculation of the number of sampling units required toachieve a preselected precision and confidence level or, alter-natively, for calculating the
4、confidence limits for the meanbased on the variability of the sample tested.NOTE 1This practice for devising a sampling plan is intended for usein connection with Test Method D 1576 or Test Method D 2462. Thesampling of raw wool for the determination of clean wool fiber present iscovered in Practice
5、 D 1060.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Refe
6、renced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 1060 Practice for Core Sampling of Raw Wool in Pack-ages for Determination of Percentage of Clean Wool FiberPresentD 1576 Test Method for Moisture in Wool by Oven-DryingD 2462 Test Method for Moisture in Wool by Distillation
7、With TolueneE 122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or Process3. Terminology3.1 Definitions:3.1.1 laboratory sample, na portion of material taken torepresent the lot sample, or the original material, and used inthe lab
8、oratory as a source of test specimens.3.1.2 lot, nin acceptance sampling, that part of a consign-ment or shipment consisting of material from one productionlot.3.1.3 lot sample, none or more shipping units taken atrandom to represent an acceptance sampling lot and used as asource of laboratory sampl
9、es.3.1.4 sample, n(1) a portion of a lot of material which istaken for testing or record purposes.(2) the group of specimens used, or observations made,which provide information that can be used for makingstatistical inferences about the population from which theywere drawn.3.1.5 sampling unit, nin
10、wool, a portion of material that istaken at one time from one physical location and that iscombined with similar portions to make up the laboratorysample.3.1.5.1 DiscussionA sampling unit may or may not havethe same physical size as a specimen. Examples of samplingunits include: (1) for bulk materia
11、ls seen as scoured wool, ahandful of wool conforming to a stated mass range, (2) forcored material, a minimum mass of material collected by oneinsertion of a coring tool, (3) for sliver, a stated length ofmaterial, and (4) a single package, such as a ball of top.3.1.6 specimen, na specific portion o
12、f a material or alaboratory sample upon which a test is performed or which isselected for that purpose.3.1.7 For definitions of moisture, moisture content, moistureregain, and other textile terms used in this practice, refer toTerminology D 123.1This practice is under the jurisdiction of the ASTM Co
13、mmittee D13 onTextilesand is the direct responsibility of Subcommittee D13.13 on Wool and Felt.Current edition approved Aug. 1, 2008. Published October 2008. Originallyapproved in 1966. Last previous edition approved in 2001 as D 2525 90 (2001).2For referenced ASTM standards, visit the ASTM website,
14、 www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4
15、. Summary of Practice4.1 Directions are given for subdividing a lot of materialinto potential sampling units and for providing each potentialsampling unit with its own unique identification.4.2 Directions are given for calculating the number of suchsampling units required to give a preselected allow
16、able varia-tion at a stated probability level, or for calculating confidencelimits for the sample mean obtained for a given size of sample.4.3 Directions are given for deciding which particular sam-pling units should be chosen to constitute the required lotsample. These directions ensure that all po
17、tential samplingunits have approximately the same chance of being selected forthe lot sample.5. Significance and Use5.1 This recommended practice furnishes directions for thesampling of wool of the various forms indicated in Section 1,in order that correct probability statements may be made aboutthe
18、 relationship between the sample mean and the populationmean. If these statements are to be correct, certain conditions,which are stated, must hold.5.2 This recommended practice requires that a deliberate actof randomization be performed so that all potential samplingunits have approximately the sam
19、e chance of being taken andno sampling unit is deprived of its chance of being taken.5.3 In any case where insufficient information about thevariability of the sampling units within the lot is available,directions are given for calculating confidence limits for thesample mean so that a correct proba
20、bility statement can still bemade.6. Preliminary Conditions6.1 If it is desired to calculate a sample size to achieve apreselected precision at a preselected level of confidence,knowledge of the variation of the moisture content is neces-sary.6.1.1 The test method to be used must be the same methodt
21、hat was used to derive any prior information with respect tothe variability of the moisture content.6.1.2 The sampling unit must be the fundamental unit interms of which the variance is expressed. In other words, if thesampling unit is chosen to be a 25-g handful of bulk materialor a 4-yd (3.65-m) l
22、ength of sliver, then the variance used mustbe the number that expresses the variability of these units, andthe number of sampling units which is calculated will be thenumber of such units required. The sampling unit is notnecessarily the same thing as a specimen.6.1.3 The lot designated for samplin
23、g must be statisticallyhomogeneous. This is equivalent to saying that the lot shall notbe composed of a mixture of two or more parts, the moisturecontent of which is distributed sufficiently differently that if themoisture content of the entire lot were measured, a plot of themoisture content versus
24、 the number of sampling units wouldshow a curve having more than one peak. (See Appendix X1.)If the test given inAppendix X1 leads to the conclusion that thelot cannot be considered to be statistically homogeneous, thenit should be subdivided into groups that are homogeneous. Thepattern of runs foun
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
10000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- ASTMD252519902008STANDARDPRACTICEFORSAMPLINGWOOLFORMOISTURE 测定 羊毛 水分 取样 标准 实施 规程 PDF
链接地址:http://www.mydoc123.com/p-513042.html